SMEFT implementation

The SMEFT implementations are (with exception of ggF HWW) not really cross-checked yet. Someone needs to take a look over the coupling generators . These two have been validated already:

 makeSMEFTggFCouplings
 makeSMEFTHWWCouplings

These still need to be validated and possibly corrected:

 makeSMEFTHyyCouplings
 makeSMEFTVBFCouplings

These ones would need to be added:

 makeSMEFTHZZCouplings
 makeSMEFTHbbCouplings
 makeSMEFTHtautauCouplings
 makeSMEFTVHCouplings
 makeSMEFTWHCouplings
 makeSMEFTZHCouplings

as well as possibly some additional ones.

Also, it would really be useful to add a constructor for

RooSMEFTHiggsMorphFunc

for modeling a process where the Higgs is only being produced (no BSM decays).